There are three types of malfunctions:<\/p>\n
- \n
- \u00a0Failure to fire<\/strong><\/span>.\u00a0 Sometimes user-error, forgetting to rack the slide.\u00a0 Otherwise, either a defective primer (ammo problem), or a light primer strike (ammo or gun problem).\u00a0 That is the subject of this article<\/strong> (this assumes that, when you press the trigger, the striker\/firing pin moves forward, and pokes through the hole in the breech face.<\/em>)<\/li>\n
- Failure to extract<\/strong><\/span>.\u00a0 After firing, the empty casing remains in the chamber, and causes a double-feed.\u00a0 Usually an extractor problem.<\/li>\n
- Failure to eject or feed<\/strong><\/span>.\u00a0 Often user-error: bad grip, but can be the gun.\u00a0 See notes below.\u00a0<\/li>\n<\/ol>\n
Notes on Type 3 malfunctions<\/strong>: when these problems persist across different shooters, the problem often stems from inconsistency of dimensional specifications during manufacture, especially in regard to magazine lips, feed ramp, or transition from feed ramp-to-chamber.\u00a0 How does that happen?\u00a0 Modern CNC Laser cutting equipment is accurate to thousandths of an inch, but even the best equipment, used 24\/7 for weeks on end, will get out of adjustment.\u00a0 It costs money to stop the line every day for several hours to make those fine adjustments.\u00a0 If they do it, anyway, the cost of the gun goes up.\u00a0 As usual, you get what you pay for.\u00a0 If they don’t do it on a timely schedule, that gun will have intermittent problems that can never be solved.<\/p>\n
Finally, back to the subject, the Type 1\u00a0 malfunction, Failure to Fire.<\/strong><\/p>\n
Among the several guns I use for teaching beginner pistol classes are a Glock 17 Gen 3 (9mm, full size, often carried by police) and a Glock 19 Gen 4 (9mm, compact size).\u00a0 These are both police trade-ins.\u00a0 They are a few years old, but in good shape.\u00a0 The ammo I use (by the case) is from a small company in Idaho.\u00a0 I have used it for years, and the quality has always been very good.\u00a0 However, they went through a buy-out and reorganization about three years ago, and Quality Control (QC) seems to have suffered a little since then.\u00a0 Duds (cartridges with defective primers) started showing up at a rate about 1% (a little high), and one cartridge showed up with bullet setback of .15 inch.\u00a0 Oops!\u00a0 I stopped using that brand for a few months, but then started back, as they ship quickly, and almost always have inventory.\u00a0 Ever since the pandemic, most ammo manufacturers have had QC problems.\u00a0 Within a month, I started seeing duds again, about 1-2 per box, but sometimes none.\u00a0 I began to think that it might be the guns.\u00a0 Since I had thought that these failures were all ammo-related, I had not made a note of which guns were affected.\u00a0 I tested the ammo with two other guns.\u00a0 They did not have a problem, but unless I shoot at least two boxes of ammo, that would not prove anything.\u00a0 One new gun in particular, a Kimber, had never had a dud with this ammo.\u00a0 I then shot some very good Remington with a Glock; no duds would likely mean it was the other ammo.\u00a0 However, I had one failure.\u00a0 That points to the gun, but not definitively.\u00a0 Any brand can have a dud.<\/p>\n
![\"\"](\"https:\/\/mckinneyfirearmstraining.com\/wordpress\/wp-content\/uploads\/2022\/11\/bullets-300x149.jpg\")
<\/p>\nL. New, unfired cartridge
R. Dud.\u00a0 Primer was struck, but failed to ignite<\/p>\nThe proof is not 100%, but the evidence points to “light primer strikes”, and getting worse.\u00a0 What to do?\u00a0 The striker (firing pin) rides in a channel inside the slide, and pokes the pointed end through a hole and into the primer.\u00a0 The possibilities include<\/p>\n
- \n
- \u00a0a weak striker spring<\/li>\n
- debris in the striker channel<\/li>\n
- the point on the striker worn off by use (however, it is steel)<\/li>\n<\/ol>\n
Replacing the striker spring would mean cleaning out the channel as well, so that takes care of two items.\u00a0 I ordered two springs.\u00a0 After cleaning the channels and replacing the striker springs on both guns, I test-fired both guns with the suspect ammo.\u00a0 The G17 went 20 in a row, no issues.\u00a0 The G19 went 25, with a failure at number 23.\u00a0 Then I got a box of Remington UMC 9mm, very good, but a little pricey for bulk use.\u00a0 The G19 went 33 in a row, no problems.\u00a0 A few minutes later, using the bad ammo, it went 12, and failed at 13.\u00a0 That cartridge was fired again, and worked, so the primer was not completely bad.\u00a0 Remember that, with one dud per box, it might be the last one in the box, so none of this proves anything.\u00a0 It still might be the ammo, but my Kimber has gone at least 150 rounds without a failure, so the gun is still a suspect.\u00a0 The next step: replace the striker.<\/p>\n
A few days later, a new striker came in the mail, with another new spring (it was a set).\u00a0 Since I now have an extra striker spring, I will put one in my Glock 23; it can’t hurt.\u00a0 Now, it is time to test the G19 again.\u00a0 Using the Remington UMC ammo, it went 15 in a row, no failures.\u00a0 Back to the suspect ammo.\u00a0 The very first round failed, along with three others in the first 40 rounds.\u00a0 I switch to the Kimber pistol, using the same suspect ammo, and it runs 20 straight with no failures.\u00a0 However, remember that this ammo has several times gone 20-30 rounds in a row with no failures.\u00a0 Remember, too, that in almost every case, when a round has failed to ignite the first time, it has worked the second time.\u00a0 That proves that the primers are not defective, per se, although they might be set too deeply in the pocket.<\/p>\n
Time to analyze the results.<\/strong>
The most likely answer is that, in 2-8% of the cartridges, the primer is either set too deeply in the pocket, or is the wrong type of primer for this loading.\u00a0 Why does the Kimber always work?\u00a0 It is likely that, being a more expensive gun, they designed it to have a stronger spring than necessary, to allow a larger margin for variance in ammo quality.<\/p>\nFinal Test.<\/strong>
After yet another inspection of the channel, and manual testing of striker action, I go to the range with three boxes of ammo:<\/p>\n- \n
- Remington UMC, a very high quality commercial brand.<\/li>\n
- Blazer, a budget brand made by a major company, CCI.<\/li>\n
- The suspect brand, but a different lot number<\/span> (an important difference).<\/li>\n<\/ul>\n
Using the Glock 19, I shot the following strings:<\/p>\n
- \n
- \u00a0Remington, 25 shots, no failures<\/strong><\/li>\n
- Blazer, 25 shots, no failures<\/strong><\/li>\n
- \u00a0Suspect brand, 50 shots, 1 failure<\/strong><\/li>\n
- \u00a0Using the Kimber and the known bad lot number, 25 shots, still no failures<\/strong><\/li>\n<\/ol>\n
My deduction now, is that probably all the guns needed was a change in ammo.\u00a0 Refreshing the striker springs was a good thing, and well worth the little they cost, but nothing else was critically necessary.\u00a0 In the bad lot of ammo, about 5% of the primers exceeded acceptable specs for installation.\u00a0 The Kimber simply has a wider tolerance than the Glocks.\u00a0 As usual, the simplest answer appears to be the best.<\/strong><\/p>\n
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Modern semi-automatic handguns are the result of well over 100 years of research and development.\u00a0 Internal operating processes are well-defined, and seldom change.\u00a0 The biggest differences between models are design, user features, and calibers.\u00a0 Maintenance is fairly simple, and handguns often go for years without needing professional service. The keyword there is “often”.\u00a0 Sometimes, guns … Continue reading “Diary of a Gun Repair”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-423","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/mckinneyfirearmstraining.com\/wordpress\/wp-json\/wp\/v2\/posts\/423","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mckinneyfirearmstraining.com\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mckinneyfirearmstraining.com\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mckinneyfirearmstraining.com\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mckinneyfirearmstraining.com\/wordpress\/wp-json\/wp\/v2\/comments?post=423"}],"version-history":[{"count":12,"href":"https:\/\/mckinneyfirearmstraining.com\/wordpress\/wp-json\/wp\/v2\/posts\/423\/revisions"}],"predecessor-version":[{"id":440,"href":"https:\/\/mckinneyfirearmstraining.com\/wordpress\/wp-json\/wp\/v2\/posts\/423\/revisions\/440"}],"wp:attachment":[{"href":"https:\/\/mckinneyfirearmstraining.com\/wordpress\/wp-json\/wp\/v2\/media?parent=423"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mckinneyfirearmstraining.com\/wordpress\/wp-json\/wp\/v2\/categories?post=423"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mckinneyfirearmstraining.com\/wordpress\/wp-json\/wp\/v2\/tags?post=423"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
- Blazer, 25 shots, no failures<\/strong><\/li>\n
- \u00a0Remington, 25 shots, no failures<\/strong><\/li>\n
- Failure to extract<\/strong><\/span>.\u00a0 After firing, the empty casing remains in the chamber, and causes a double-feed.\u00a0 Usually an extractor problem.<\/li>\n